Cutting device for a moving web

ABSTRACT

A rotatable cutter member is mounted on a movable carrier such that its center of gravity is located on the shaft connected to the movable carrier. Thus, the cutter member can freely position itself relative to a moving web that is to be cut without introducing unwanted tension or an irregular cut line. A guide track supports the movement of the carrier while the cutter member forms a V-notch cutting edge.

United States Patent 1191 1111 3,765,292 Fujiwara Oct. 16, 1973 [54]CUTTING DEVICE FOR A MOVING WEB 2,620,993 12/1952 Jeffrey, .lr 83/6143,236,136 2/1966 83/614 [75] Invent Fuliwal'a Kanagawa 3,213,735 10/1965Keferstein et a1 83/353 mm E22 2,283,838 5/1942 Williams 83/353 x [73]Assignee: Fuji Photo Film Co.,Ltd.,

Mm l a n z rgatv z l apan Primary Examiner-J. M. Meister Filed: 1 Dec.1971 Attorney-Richard C. Sughrue et al.

[21] Appl. No.2 209,212 [57] ABSTRACT A rotatable cutter member ismounted on a movable [30] Forelgn Apphcanon Pmmty Dam carrier such thatits center of gravity is located on the Dec. 17, 1970 Japan 45/113921haft connected to the movable carrien Thus the cutter member can freelyposition itself relative to a mov- [52] US. Cl. 83/614, 83/353 ing webthat is to be cut without introducing unwanted Cl 526d 7/26, 326d 1/04tension or an irregular cut line. A guide track supports Field 83/353,614 the movement of the carrier while the cutter member 1 forms aV-notch cutting edge. [56] References Cited r 5 Clfllms, 2 DrawingFigures 3,365,992 1/1968 Dreher 83/614 VARIABLE SPEED DRIVE CUTTINGDEVICE FOR A MOVING WEB BACKGROUND OF THE INVENTION 1. Field of theInvention The present invention provides a cutting device for cutting amoving web wherein the cutting element is rotatably mounted on a shaftwhich is in turn mounted on a moving station. More particularly, thepresent invention is directed to a device for cutting a moving web atany angle such as a moving web of plastic film traveling in a straightline.

2. Description of the Prior Art Cutting devices for cutting moving webshave been known in the prior art and particularly, there is a device forcutting thin paper that utilizes a sawtooth cutting edge. The cuttingdevice, however, affects the continuity of flow of the moving webmaterial and leaves a jagged or uneven cutting line. As a result of theirregular cutting line, the web is not readily adaptable to be wound ona core to produce a roll. Generally, for example, a film is immediatelywound after the cutting step and an uneven cutting line will tend tobend or wrinkle the film member. In addition, the operation of asawtooth cutter has been found to be dangerous in the industry.

In addition, when a plastic film web is to be cleanly cut in a linearfashion, a rotating circular edge has been utilized to move along theopposite edge so as to both out and tentatively stop the moving webduring the operation.

The prior art has been plagued with problems of accuracy and with safetyproblems related to the rotating blade member. In thos cases where themoving web is stopped temporarily for cutting, it is often necessary toprovide an accumulator or reservoir to permit the continual processingand production of the web member.

SUMMARY OF THE INVENTION It is therefore an object of the presentinvention to provide a device for cutting a moving web such as a plasticfilm which eliminates the aforementioned disadvantages of theconventional cutting devices utilized in the prior art. It is further anobject of the present invention to provide a cleanly cut edge at anylinear angle. The present invention permits the cutting of a moving webwithout any danger to the operator. Basically, the present inventionprovides a cutting element which is rotatably mounted on a shaft whichis in turn mounted on a movable carrier that can be driven or pulledacross the path of the moving web.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantagesof this invention will become apparent from the following descriptiontaken in conjunction with the accompanying drawings, in'which:

FIG. 1 is a perspective view of the cutting device constructed inaccordance with the present invention, and

FIG. 2 is a plan view of the cutting device during operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the above drawings,a cutter 9 is mounted on a cutter moving device or carrier 1. The cutter9 is constructed as disclosed in FIG. 1, with a cutting edge of a pairof scissor type cutters. The cutter edge 5 is provided on a cutter beammember 4 which in turn is mounted on a shaft 3 mounted on the cuttermoving device I. The cutter 9 is rotatably mounted via the cutter shaft3 by a bearing 2 on the carrier 1, so that it is rotatable about theaxial center 00'. The cutter beam member 4 is balanced so that thecenter of gravity of the cutter 9 lies on the axial shaft 3.

The web cutting point C of the cutter edge 5 is provided at a positiondisplaced in the amount of r from the axial center 00'. A cutter movingdevice 10 comprises a chain, wire or shaft 6, for driving the cutter andis connected to a variable speed motor or other appropriate means forvarying the speed of the cutter. A guide rail 7 controls the movement ofthe cutter device as it is driven.

In operation, the cutter device is pulled or driven across a movingplastic web as disclosed in FIG. 2 and in the process cuts the webwithout any deformation. The guide rail 7 is positioned so that the webcutting point C of the cutting edge 5 of the cutter 9 is disposed on thesame plane as the plane that the web is moving.

If the cutter 9 is moved at a speed of Vc perpendicularly to the web 8moving at a speed of Vw, the web cutting point C of the cutter edge 5,will adjust itself corresponding to the two relative speeds to provide acutting angle relative to the movement of the web such that O tan"Vw/Vc.Generally, it is preferable that cutting edge 5 be prealigned along the9 angle to insure a linear cut. When the cutting edge 5 engages the web,it is preferred that the cutting edge be completely free so that it iscapable of rotating about the shaft 3. This permits the direction of thecutter 9 to be automatically determined only by the web speed Vw and themoving speed Vc of the cutter 9. The angle cut on the moving web may bevaried by adjusting both the guide track 7 and the speed of the cutter 9by, for example, a variable speed motor means. It has been found thateven if the moving speed Vw of the web and the moving speed Vc of thecutter 9 change during the cutting operation, the only result is thatthe cutting line will curve, but will not produce any defects.

It should be understood from the above description that since the webcutting point C follows without difficulty with respect to the movementof the cutter shaft 3 by displacing the web cutting point C of thecutting edge 5 in the amount r from the axial center to automaticallydetermine the angle 6 formed between the direction of the cutter edgeand the moving direction of the cutter 9. Since the cutter is freelyrotatable, there is no adverse tension applied to the web and accordingly, any buckling or jagged cuts will not occur.

It should also be noted that since the sharp edge of the cutter 9 is notexposed except when the cutteris moving during the invention, thecutting edge may become compact and be appropriately guarded to providea safe operation for an operator in comparison with the conventionaldevice.

It should also be understood that since the device may gradually cut theweb at an angle 6 tan Vw/Vc, the tension of the moving web will not beabruptly affected by the cutting and since it will produce a sharp end,it will be easy for insertion into a new core for winding purposes.

Since various modifications can be made by a person skilled in the art,it is clear that the scope of the present invention should be measuredfrom the following claims.

What is claimed is:

1. A cutting assembly for cutting a relatively moving member with aminimum of tension in the member comprising:

a carrier member;

guide means for the carrier member;

means for moving the carrier member,

cutter means mounted on the carrier member and freely rotatable relativeto the moving member for cutting the moving member as a function of thespeed of the carrier member and the moving memher, said cutter meansincluding a support member and a cutter blade, said cutter blade beinglocated at one end of the support member, a shaft connectspeed meansdrives the carrier member.

3. A cutting assembly as in claim 1, where the guide means includes atrack.

4. A cutting assembly as in claim 1, where the support member is counterbalanced with respect to the weight of the cutter blade.

5. A cutting assembly as in claim 2, where the cutting angle between themoving member and the cutter blade is 6 tan' VwlVc, where Vw equalsmoving member velocity and V0 equals cutter blade velocity.

1. A cutting assembly for cutting a relatively moving member with aminimum of tension in the member comprising: a carrier member; guidemeans for the carrier member; means for moving the carrier member,cutter means mounted on the carrier member and freely rotatable relativeto the moving member for cutting the moving member as a function of thesPeed of the carrier member and the moving member, said cutter meansincluding a support member and a cutter blade, said cutter blade beinglocated at one end of the support member, a shaft connecting the supportmember to the carrier member at the center of gravity of the supportmember and the cutter blade and said cutter blade being V-shaped andfixed relative to said support member.
 2. A cutting assembly as in claim1, where a variable speed means drives the carrier member.
 3. A cuttingassembly as in claim 1, where the guide means includes a track.
 4. Acutting assembly as in claim 1, where the support member is counterbalanced with respect to the weight of the cutter blade.
 5. A cuttingassembly as in claim 2, where the cutting angle between the movingmember and the cutter blade is Theta tan 1Vw/Vc, where Vw equals movingmember velocity and Vc equals cutter blade velocity.